As Monsieur G. Auguste Dupin and his friend sit smoking their meerschaums in the library at No. 33 Rue Dunot, their thoughts and contemplations are interrupted by the arrival of Monsieur G---, the Prefect of the Parisian Police. Why do Dupin and the narrator welcome the Prefect so heartily, and what does the wording of their reasons suggest about the character of their uninvited guest?